1. Technical Field of the Invention
This invention relates generally to portable electronic equipment, and more particularly to a multi-function handheld device that employs a memory having hidden memory blocks to store operating system programs.
2. Description of Related Art
As is known, integrated circuits are used in a wide variety of electronic equipment, including portable, or handheld, devices. Such handheld devices include personal digital assistants (PDA), CD players, MP3 players, DVD players, AM/FM radio, a pager, cellular telephones, computer memory extension (commonly referred to as a thumb drive), etc. Each of these handheld devices include one or more integrated circuits to provide the functionality of the device. For example, a thumb drive may include an integrated circuit for interfacing with a computer (e.g., personal computer, laptop, server, workstation, etc.) via one of the ports of the computer (e.g., Universal Serial Bus, parallel port, etc.) and at least one other memory integrated circuit (e.g., flash memory). As such, when the thumb drive is coupled to a computer, data can be read from and written to the memory of the thumb drive. Accordingly, a user may store personalized information (e.g., presentations, Internet access account information, etc.) on his/her thumb drive and use any computer to access the information.
As another example, an MP3 player may include multiple integrated circuits to support the storage and playback of digitally formatted audio (i.e., formatted in accordance with the MP3 specification). As is known, one integrated circuit may be used for interfacing with a computer, another integrated circuit for generating a power supply voltage, another for processing the storage and/or playback of the digitally formatted audio data, and still another for rendering the playback of the digitally formatted audio data audible.
Integrated circuits have enabled the creation of a plethora of handheld devices, however, to be “wired” in today's electronic world, a person may need to posses multiple handheld devices. For example, one may own a cellular telephone for cellular telephone service, a PDA for scheduling, address book, etc., one or more thumb drives for extended memory functionality, an MP3 player for storage and/or playback of digitally recorded music, a radio, etc. Thus, even though a single handheld device may be relatively small, carrying multiple handheld devices on one's person can become quite burdensome.
In a typical hand-held device, an integrated circuit that contains a processor or a controller generally loads a boot program from a memory device, such as a read only memory (ROM). In some instances the boot program is stored on a writable memory device, so that the boot program may be updated or reloaded with different versions of the booting program. In some instances, a NOR type flash memory device may be employed to store the boot program, since NOR flash memories are more suited for this type of operation. Accordingly, it is a typical practice to employ a ROM or a NOR flash memory for booting when the device is initialized. The advantage of the use of a flash memory is that the boot program may be customized. Furthermore, the flash device may be updated with newer or different boot programs.
Even though a ROM or a NOR flash memory device is employed with a processor, the actual data storage is performed utilizing other types of memory storage devices. For example, if the flash technology is employed, typical practice is to employ a NAND type flash memory device for mass storage of data, since NAND flashes are more suited for mass data storage. Therefore, prior art practice has been to employ a ROM or NOR type flash memory for storage of booting programs, while NAND type flash storage devices are utilized for the storing of data. Accordingly, embodiments of the present invention addresses a scheme in which both a boot program is stored on the same storage media as data, so that one type of storage device may be utilized to store both the boot program and data.